1. Field of the invention
The present invention relates to the forming of structural assemblies and, more particularly, relates to a method and preform for forming a structural assembly that defines at least one formed skin member and at least one support member.
2. Description of Related Art
Various methods are known for manufacturing structural assemblies having contoured configurations. According to one conventional method of manufacture, a structural assembly is produced by first forming a number of structural members and then assembling the structural members. Each of the structural members can be formed to a shape that defines a portion of the assembly, and, in this way, the structural members can be assembled to define a shape in combination that would be difficult or impossible to form as a single member. For example, in one typical method of forming the inlet of a nacelle of an aircraft engine, several portions that define the cross-section shape of the inlet are formed, e.g., by superplastic forming, and the separate portions are then assembled circumferentially so that each portion defines a portion of the inlet.
In some cases, it is desirable to form a part as a single assembly so that multiple members do not have to be connected after forming. For example, parts used in some aerospace applications require specific aerodynamic characteristics. In particular, the smoothness of parts defining the outer surfaces of aircraft and other vehicles can affect the flow of air around the aircraft. For example, if the leading edge of an engine nacelle or other body portion of an aircraft is formed of multiple members, the interfaces of the members may disrupt the flow of air around the aircraft, thereby potentially affecting the performance and efficiency of the aircraft.
Thus, there exists a need for an improved method for forming structural assemblies and an associated preform and assembly. The method should be capable of forming a variety of desired contours, and should be capable of forming the assembly with a smooth other surface as desired for some applications. In addition, the method should be compatible with materials such as titanium.